Vibration-meter.



E. H. THOMPSON.

VIBRATION METER.

APPLICATION FILED MAR. I9, ISI?,l

1,293,984. e Patented Feb. II, 1919.

Eli Thompson, a5

Yi/WW www EUSTIS HENRY THOMPSON, 0F BALTIMORE, MARYLAND.

'VIBRATION-METER.

Specication of Letters Patent.

Patented Feb. 11, 1919.

Application led March 19, 1917. Serial N o. 155,961.

To all 'whom t may concern.'

Be it known that I, EUsTIs HENRY THoMP- SON, a citizen of the United States, residing at Baltimore, State of Maryland, have invented certain new and useful Improvements in Vibration-Meters; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which lit appertains to make and use the same.

This invention relates to vibration meters and has for its object to provide a device of this character which will be comparatively inexpensive to manufacture and more eiicient in action than those heretofore proposed.

With these and other objects in view the invention consists in the novel details of construction and combinations of parts more fully hereinafter disclosed and particularly pointed out in the claims.

Referring to the accompanying drawings forming a part of this specification in which like numerals designate like parts in all the views:

Figure 1 is a diagrammatic elevational view of one form of the invention;

Fig. 2, is a view similar to Fig. 1 illustrating a modified form of the invention; and

Fig. 3 is a view illustrating a still further modified form of the invention.

1 indicates any support or other body the vibrations of which are to be investigated; 2, a bracket rigid with said body, provided with the Contact button or face 3, and 4 represents a movable member provided with the contact surface 5, and having pivotally attached thereto as at 6 and 7 respectively the upright members 8 and 9. Said members 8 and 9 are respectively pivotally attached as at 10 and 11 to the bracket or support 12, mounted as at 13 on the support 14. The upright member 8 is provided with an extension 15 to which is attached as at 16 one end of the spring member 17 the other end 18 of which is secured to the spring meter 19 having the pointer 2O and dial 21. Also attached to the said meter 19 and controlling the tension of said spring 17 is one end 22 of the rod 23 having the handle 24 at its other end and between its ends the detent 25 adapted to engage the rack 27 carried by the bracket 12.

Said upright member 9, has attached thereto at the point 30 one end of the spring 31, the other end of which is attached to the ad- J in s, J

justable screw threaded member 32 passing through said bracket 12 and secured in place as by the nut 33. Also passing through said bracket 12 is the screw member 35 the pointed end 36 of which contacts with the surface 37 of said horizontally disposed member 4.

Leading from the contact member 3 is the wire 40 joined to the battery 41, and leading from said battery to the bracket member 12 is the wire 42, the lamp 43 being joined in the circuit as shown. Also leading from said contact member 3 is the wire 44 joined to the battery 45, leading from said battery to one end of the coil 47 is the wire 46, and leading from the other end of said coil to the member 4 is the wire 48. Inductively connected with the coil 47 is the coil 49, and joining the ends of said last named coil to the ammeter 50 is the wire 51.

The operation of the apparatus so far disclosed is as follows: Supposing that the member 1 is the vibrating pillow block of a turbine or other engine, and it is desired to measure its vibrations, the parts being at rest are so adjusted that the surfaces 3 and 5 just touch each other. This adjustment is conveniently accomplished by means of the screw 32 and spring 31, and the lighting up and dimming of the lamp 43 will indicate when the parts arel properly adjusted to their Zero position. After this is done and the part is vibrating the rod 23 and detent 25 is adjusted along` its rack 27 to put a sufficient tension on the spring 17 to hold the surfaces 3 and 5 in contact against the tendency of the vibrations to separate them. The greater the vibrations of the pillow block 1 the greater will be the tension that must be put on to said spring 17 to balance the force tending to separate the surfaces 3 and 5 and to just prevent the lamp 43 from iickering. The pointer 20 of the spring balance, or meter 19 will indicate what this force is; and therefore said pointer and scale 21 really measure the throw, or extent of vibration of said pillow block as will now appear.

This will be clear when it is remembered that as the pillow block vibrates, its motion to the right, for example, begins at zero and progressively reaches a maximum and then it gradually returns to zero a ain. Were the surface 5 and the member 4 ee to move they would when this maximum velocity had been reached be thrown toward the right by the force of their momentum, and thus the circuit through the lamp would be broken. On the other hand when a force is applied, as that caused by the spring 17, which is equal and opposite to the force tending to separate these surfaces, then the said surfaces will not separate, but will remain in contact throughout the motion mentioned. Not only will said spring 17 thus keep the surfaces 3 and 5 in contact during the movement of the pillow block in one direction, but a little consideration will show that said surfaces will in the same way be kept in contact throughout the entire cycle of movement. A little consideration will further show that the greater the throw of the pillow block the greater will be the said momentum and degree to which said spring 17 must be tensioned and that therefore the spring balance 19 will measure the extent of said vibrations, the lamp 43, serving at all times to indicate when the parts are in correct adjustment.

Supposing the vibrations measured are caused by the revolution of the shaft 55, it can be proved that the maximum force of vibration will vary as the square of the number of revolutions per unit of time, and therefore a record of the meter 19 for one speed can be corrected for another know speed.

Supposing the surfaces 3 and 5 to be so adjusted as to just be out of contact, the speed of the shaft 55 is conveniently measured as follows: Since the current through the now very loose contact between the surfaces 3 and 5 and through the coil 47 will greatly vary at each half period of vibration, an alternate current ammeter 50 will measure the total current passing from the constant voltage battery 45, if the constants of the coils 47 and 49 are known and this total current will be proportional to the speed of rotation of the shaft 55.

In properly adjusting the contacts 3 and 5 for measuring the speed of the shaft 55, the screw member 35 may be utilized by so 'moving it as to limit the extreme movement of the surface 5.

In the form shown in Fig. 2 the construction is substantially the same as that above disclosed the battery 45 and its associated parts, and the screw 35 and bracket 12 being omitted. Instead of the bracket 12 the parts are supported from the bracket 60 mounted on the block 1. This form gives all the data that is usually required in commercial practice and may therefore be called the commercial form of the invention while the form shown in Fig. 1 is more suitable for the laboratory.

The form shown in Fig. 3 is somewhat similar to that shown in Fig. 2, except the bracket 60 is omitted, and the members 4, 8 and 9 are supported from the member 61 by means of the handle 62, a spirit level 63 being carried by the member 61 to indicate when the parts are in their proper positions. In this form of the invention the gravity of the parts is relied on to maintain the contact between the surfaces 3 and 5, and the displacement of the pointer 64 on the scale 65 will be a measure of the force or thrust of the surface 5 toward the left that is found necessary to just keep the lamp 43 lighted, and of course this said force will in turn be a measure of the throw of the pillow block.

In all the forms it will now be seen I provide a means for maintaining the surfaces 3 and 5 in contact throughout the cycle of vibratory movement, that I also measure the extent of movement of the Vibratory body, and that through the lamp circuit I indicate whether or not the parts are functioning properly. In Fig. 1, in addition to this, I may measure the speed of rotation of the shaft, or the number of vibrations produced in a given time.

It is obvious that those skilled in the art may vary the arrangement of parts as well as the details of construction without departing' from the spirit of the invention and therefore I do not wish to be limited to the above disclosure except as may be required by the claims.

That I claim is:

1. In a vibration meter the combination of means for contacting with a vibrating body; means associated with said contacting means adapted to measure the force exerted by the latter on said vibrating body; and means comprising an electric circuit joining said irst named means and body to indicate when the parts are properly adjusted, substantially as described.

In a vibration meter the combination of a movable member adapted to lightly contact with a vibratin body; means including an electric circuit or indicating when the proper contact is had; and means comprising a spring connected with said member and under tension for measuring the throw of said vibrating body, substantially as described.

3. In a vibration meter the combination of a movable member adapted to lightly contact with a vibrating body; a spring controlled member for adjusting the contact of said first named member with said body; an electric lamp and a circuit including said first named member for indicating when the parts are in proper adjustment; a meter provided with a spring for measuring the throw of said vibrating body; and means for adjusting the tension of said last named spring. substantially as described.

4. In a vibration meter the combination of a movable member adapted to lightly contact with a vibrating body; a circuit including said movable member and vibrating body provided with a coil having inductance; a second circuit and coil in inductive relation to said irst named coil; and an alternating current meter in said second circuit, Whereby the total vibrations per minute of said body may be ascertained, substantially as described.

5. In a vibration meter the combination of a movable member adapted to lightly contact With a vibrating body; an adjustable member adapted to limit the movements of said rst named member; means to adjust said first named member in a predetermined relation to said vibrating body;

a circuit including said movable member 15 and vibrating body provided with a coil having inductance; a second circuit and coil in inductive relation to said rst named coil; and an alternating current meter in said second circuit, whereby the total vibra- 20 tions per minute of saidvbody may be ascertained, substantially as described.

In testimony whereof I ax my signature, in presence of two Witnesses.

v EUSTIS HENRY THOMPSON. Witnesses:

MARY LANGLoTz, HENRY ROBERG.

copie: o! this patent may be obtained for ve cents each, by addressing the Commissioner of Patenti. Washington, D. c." 

